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Response snapshot Oct 27, 2026, 01:26 UTC

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VulnerabilityCVE-2026-42271Known exploitation

BerriAI LiteLLM Command Injection Vulnerability

LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. From version 1.74.2 to before version 1.83.

At a glance

Exploited
Yes: on CISA's Known Exploited list
Severity
8.7 High (CVSS 4.0)
Chance of exploitation
91.4% in the next 30 days
CISA federal deadline
Jun 22, 2026: passed
Sources
4 independent sources

What to do

Check the vendor advisory for affected versions and fixes.

CISA's required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Read NVD CVE-2026-42271 (opens a new tab)

What happened

LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. From version 1.74.2 to before version 1.83.7, two endpoints used to preview an MCP server before saving it — POST /mcp-rest/test/connection and POST /mcp-rest/test/tools/list — accepted a full server configuration in the request body, including the command, args, and env fields used by the stdio transport.

When called with a stdio configuration, the endpoints attempted to connect, which spawned the supplied command as a subprocess on the proxy host with the privileges of the proxy process. The endpoints were gated only by a valid proxy API key, with no role check. Any authenticated user — including holders of low-privilege internal-user keys — could therefore run arbitrary commands on the host.

This issue has been patched in version 1.83.7.

CISA federal deadline

Federal due date passed

Applies to covered US federal agencies; it is not your organization's deadline.

Added to the catalog Known ransomware use: Unknown
CISA catalog (opens a new tab)

Scores and how they were measured

CVSS base severity

8.7

Version 4.0As of

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

91.4%

Scored Percentile 99.8%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-42271 (opens a new tab)

    NVD record: description, CVSS, affected products, and a CISA SSVC assessment reporting active exploitation.

    Published Checked

  2. Primary source

    Vendor advisory (via NVD references) (opens a new tab)

    The vendor advisory referenced by the CVE record, for affected versions and fixes.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  5. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  6. Primary source

    CISA KEV entry CVE-2026-42271 (opens a new tab)

    The CVE-2026-42271 catalog entry establishes known exploitation, date added, required action, and the federal due date; not zero-day status.

    Published Checked

  7. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-42271, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

  8. Primary source

    CVE Program CNA GitHub_M (opens a new tab)

    The published CVE-2026-42271 document's CNA supplies this CVSS 4.0 base score, vector, and authoritative source update date.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 26). BerriAI LiteLLM Command Injection Vulnerability (CVE-2026-42271). https://kevwire.com/record/CVE-2026-42271

MLA

"BerriAI LiteLLM Command Injection Vulnerability (CVE-2026-42271)." KEVWire, 26 Oct. 2026, kevwire.com/record/CVE-2026-42271.

Chicago

KEVWire. "BerriAI LiteLLM Command Injection Vulnerability (CVE-2026-42271)." Last modified October 26, 2026. https://kevwire.com/record/CVE-2026-42271.

Evidence summary (plain text)

BerriAI LiteLLM Command Injection Vulnerability (May 8, 2026).
LiteLLM is a proxy server (AI Gateway) to call LLM APIs in OpenAI (or native) format. From version 1.74.2 to before version 1.83.7, two endpoints used to preview an MCP server before saving it — POST /mcp-rest/test/connection and POST /mcp-rest/test/tools/list — accepted a full server configuration in the request body, including the command, args, and env fields used by the stdio transport. When called with a stdio configuration, the endpoints attempted to connect, which spawned the supplied command as a subprocess on the proxy host with the privileges of the proxy process. The endpoints were gated only by a valid proxy API key, with no role check. Any authenticated user — including holders of low-privilege internal-user keys — could therefore run arbitrary commands on the host. This issue has been patched in version 1.83.7.
CVSS 8.7 (version 4.0; evidence as of May 8, 2026; https://cveawg.mitre.org/api/cve/CVE-2026-42271).
EPSS 91.4% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-42271&date=2026-10-26).
Sources:
NVD CVE-2026-42271: https://nvd.nist.gov/vuln/detail/CVE-2026-42271
Vendor advisory (via NVD references): https://github.com/BerriAI/litellm/security/advisories/GHSA-v4p8-mg3p-g94g
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T20:05:59.720Z&lastModEndDate=2026-10-26T21:35:56.549Z&resultsPerPage=500&startIndex=1500
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T19:31:27.927Z&lastModEndDate=2026-10-26T21:05:56.246Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T19:01:15.495Z&lastModEndDate=2026-10-26T20:30:55.133Z&resultsPerPage=500&startIndex=500
CISA KEV entry CVE-2026-42271: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-42271&date=2026-10-26
CVE Program CNA GitHub_M: https://cveawg.mitre.org/api/cve/CVE-2026-42271
Record ID: CVE-2026-42271.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Documented by a cited source.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
CISA federal due date: Jun 22, 2026. This is a deadline for covered US federal agencies, not the reader's SLA.
About this data

This record was ingested from a data source. Retrieved: Oct 26, 2026, 19:40 UTC. Ingestion is not an independent editorial investigation.

NVD status: Analyzed. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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